1. Field of the Invention
The present invention relates to an intruder barrier and in particular, to an intruder barrier of the type which is rotatably mounted on the top of a wall whereby a person attempting to pass over the barrier is prevented from obtaining an effective hand-grip on either the wall or barrier.
2. Description of the Prior Art
In many instances where security devices are required, they are not required to provide an absolute bar to the professional or skilled thief but are more often required to deter vandals or, for example, where there is a likelihood of danger, to prevent children and other unauthorised personnel entering a premises. This is particularly the case, for example, in power stations and the like premises where the perimeter walls, fences and portions of the building musts be so protected as to prevent children and other unauthorised personnel climbing on to or over them. Thus, there are many cases where the security device is not so much to prevent unauthorised entry of the professional thief as to provide a safety device which will prevent untoward accidents. Needless to say, in the latter case the security aspect in also important.,
Static barriers are well known such as for example, spiked railings, barbed wire or pieces of broken glass embedded in the top of the wall. While some of these methods may restrict the activities of vandals unfortunately, they are not particularly efficient and can be readily easily overcome. More importantly they present a considerable safety hazard.
Further it is known from British Patent Specification No. 612,265 to provide apparatus for preventing or obstructing the scaling of walls, fences and the like barrier which comprises a substantially cylindrical member constituted by a series of rods, bars or sheet material arranged around the perimeters of a number of co-axial discs to produce a cage-like body mounted to rotate on bearing brackets adapted to be secured to the top of a wall or fence. Such devices consist, in their simplest form, of a substantially cylindrical member mounted in bearings to rotate on a substantially horizontal axis along a wall or fence top whereby a person attempting to pass over the barrier is prevented from obtaining an effective handgrip on the wall or barrier which rotates. These devices can be readily easily jammed in one position so that it is then only a question of climbing over a stationary barrier. Thus these devices while more suitable than spiked railings, barbed wire or capping members with inserted broken glass are not, unfortunately, as suitable as they could be for the purpose.
In Deutsche Offenlegungsschrift No. 2,206,436 there is described an intruder barrier substantially similar to the intruder barrier of British Patent Specification No. 612,265 except that this intruder barrier is mounted on a support so as to be movable at least partly at right angles to its longitudinal direction. Generally the device is roughly vertically displaceable, however, this intruder barrier is not necessarily any more efficient in use than the simpler constructions of intruder barrier and additionally, is more complex and costly to manufacture.
The tern "wall" is used in this specification not only to designate a solid wall such as a conventional perimeter wall but also a wall forming part of a building or any type of fence or railing. Additionally, the term "wall" includes the sides of any structure such as a tower or structural steel building or support. The object of the present invention is to provide an improved intruder barrier of the type hereandbefore described which will be efficient in operation while at the same time relatively inexpensive to manufacture.
A further object of the invention is to provide an intruder barrier which will not constitute a man-trap in use.
A still further object of the invention is to provide an intruder barrier that will be particularly userful for mounting on easy scale perimeter fences, for example, chain link fences.